[jrchmnd]

Hi All, first and foremost I am new to the forum as well as new to the bike community. I was lucky enough to pick up a mint 81 CM400 with decent miles as a starter bike. Now my background comes from Cars, not much knowledge of Motorcycles which I have no problem learning.

Now onto the real question, I have done a quite extensive research based on this question (believe me I have spent hours, if not days looking through forums & search engines.)

Im planning to rid of the OEM trumpet exhaust tips and replacing regular pipes (straight pipe) which I will be coating with high temp paint, as well as getting rid of the Power Chamber. So basically I will cut everything off from Power Chamber & Down then weld new pipes in which I will be the same diameter of the OEM headers.

1. Will I need to Re-Jett my carbs? (which i dont mind doing)
2. If I get the same diameter of exhaust tips will I still need to Re-jett my carbs? (kinda similar question to #1)

Any Input's would be helpful! Thanks!

 

[bilbikek411]

I recommend that you keep the stock system for the best all-around power.

 

[jrchmnd]

Hi Bill,

As much as I would like to, Its my second nature to modify all things to my liking. Ive considered, but Im just not a big fan of the oem trumphet exhaust tips. Maybe I could leave the power chamber on insead?

 

[bilbikek411]

Hi Bill,

As much as I would like to, Its my second nature to modify all things to my liking. Ive considered, but Im just not a big fan of the oem trumphet exhaust tips. Maybe I could leave the power chamber on insead?

Yeah,leave that power chamber on

 

[Old Putz]

...Maybe I could leave the power chamber on insead?

This.

You have about a zillion choices in mufflers of various shapes, sizes, and efficiencies that will bolt up to the Power Chamber. You'll save yourself a ton of time and grief by not ditching the Power Chamber and/or the airbox.

I ended up using cast-off Harley mufflers on my CM450e bobber- they work and sound great, and cost me nothing except the time and effort to make mounts for them:

http://www.hondatwins.net/forums/1-project-logs/41082-822-cm450e-bobber.html

 

[jrchmnd]

Yeah,leave that power chamber on

This.

You have about a zillion choices in mufflers of various shapes, sizes, and efficiencies that will bolt up to the Power Chamber. You'll save yourself a ton of time and grief by not ditching the Power Chamber and/or the airbox.

I ended up using cast-off Harley mufflers on my CM450e bobber- they work and sound great, and cost me nothing except the time and effort to make mounts for them:

http://www.hondatwins.net/forums/1-project-logs/41082-822-cm450e-bobber.html

So, as long as I do not modify the stock airbox & power chambers I should be fine without having to Re-jett my carbs? My main goal is to build this bike to my liking with chump-change as my main focus are on my Subaru.. Thanks for your help btw guys, thank goodnes this forum have some helpful people!

 

[longdistancerider]

I suggest increasing the primary main jet one size, these were delivered running on the lean side and this corrects that. There's a sticky in the Carb section that will tell you what jets are in which carbs from the factory.
Definitely keep the power chamber and the air box if you want trouble free riding and maintenance. There's a sticky explaining power chambers in the Misc section I think. If you were to go to straight pipes you'd be using 1.375" pipe since the primary pipes are actually double walled.
To date everyone has been happy with the sound/tone of the Sportster mufflers. Local HD dealers and shops sometimes give them away just to get rid of their pile of take offs

 

[jrchmnd]

I suggest increasing the primary main jet one size, these were delivered running on the lean side and this corrects that. There's a sticky in the Carb section that will tell you what jets are in which carbs from the factory.
Definitely keep the power chamber and the air box if you want trouble free riding and maintenance. There's a sticky explaining power chambers in the Misc section I think. If you were to go to straight pipes you'd be using 1.375" pipe since the primary pipes are actually double walled.
To date everyone has been happy with the sound/tone of the Sportster mufflers. Local HD dealers and shops sometimes give them away just to get rid of their pile of take offs

Oh Wow,

Thank you very much for the Specifics. It will be handy later on once I do the transition.